/*
 *                      GPAC - Multimedia Framework C SDK
 *
 *			Authors: Jean Le Feuvre, Pierre Souchay
 *			Copyright (c) Telecom ParisTech 2000-2012
 *                                      All rights reserved
 *
 *  This file is part of GPAC / common tools sub-project
 *
 *  GPAC is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  GPAC is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#ifndef _GF_CACHE_H_
#define _GF_CACHE_H_

/*!
 *      \file <gpac/cache.h>
 *      \brief HTTP Cache management.
 */

/*!
 *      \addtogroup dld_grp Downloader
 *      \ingroup utils_grp
 *      \brief HTTP Downloader Cache
 *
 *      This section documents the file HTTP caching tools the GPAC framework.
 *
 *      @{
 */


#ifdef __cplusplus
extern "C" {
#endif

#include <gpac/tools.h>

/**
 * Handle for Cache Entries.
 * You can use the gf_cache_get_* functions to get the cache properties
 */
typedef struct __DownloadedCacheEntryStruct * DownloadedCacheEntry;


typedef struct __CacheReaderStruct * GF_CacheReader;

/**
 * Free The DownloadedCacheEntry handle
 * \param entry The entry to delete
 * \return GF_OK
 */
GF_Err gf_cache_delete_entry( const DownloadedCacheEntry entry );

/**
 * Get the ETag associated with this cache entry if any
 * \param entry The entry
 * \return The ETag if any was defined, NULL otherwise
 */
const char * gf_cache_get_etag_on_server( const DownloadedCacheEntry entry );

/**
 * Set the eTag in the cache. Data is duplicated, so original string can be freed by caller.
 * \param entry The entry
 * \param eTag The eTag to set
 * \return GF_OK if entry and eTag are valid, GF_BAD_PARAM otherwise
 */
GF_Err gf_cache_set_etag_on_disk(const DownloadedCacheEntry entry, const char * eTag );

/**
 * Get the ETag associated with this cache entry if any
 * \param entry The entry
 * \return The ETag if any was defined, NULL otherwise
 */
const char * gf_cache_get_etag_on_disk( const DownloadedCacheEntry entry );

/**
 * Set the eTag in the cache. Data is duplicated, so original string can be freed by caller.
 * \param entry The entry
 * \param eTag The eTag to set
 * \return GF_OK if entry and eTag are valid, GF_BAD_PARAM otherwise
 */
GF_Err gf_cache_set_etag_on_server(const DownloadedCacheEntry entry, const char * eTag );


/**
 * Get the Mime-Type associated with this cache entry.
 * \param entry The entry
 * \return The Mime-Type (never NULL if entry is valid)
 */
const char * gf_cache_get_mime_type( const DownloadedCacheEntry entry );

/**
 * Set the Mime-Type in the cache. Data is duplicated, so original string can be freed by caller.
 * \param entry The entry
 * \param mime_type The mime-type to set
 * \return GF_OK if entry and mime-type are valid, GF_BAD_PARAM otherwise
 */
GF_Err gf_cache_set_mime_type(const DownloadedCacheEntry entry, const char * mime_type );

/**
 * Get the URL associated with this cache entry.
 * \param entry The entry
 * \return The Hash key (never NULL if entry is valid)
 */
const char * gf_cache_get_url( const DownloadedCacheEntry entry );

/**
 * Get the Hash Key associated with this cache entry.
 * \param entry The entry
 * \return The Hash key (never NULL if entry is valid)
 */
const char * gf_cache_get_hash( const DownloadedCacheEntry entry );

/**
 * Tells whether a cache entry should be cached safely (no
 * \param entry The entry
 * \return 1 if entry should be cached
 */
Bool gf_cache_can_be_cached( const DownloadedCacheEntry entry );

/**
 * Get the Last-Modified information associated with this cache entry.
 * \param entry The entry
 * \return The Last-Modified header (can be NULL)
 */
const char * gf_cache_get_last_modified_on_disk ( const DownloadedCacheEntry entry );

/**
 * Get the Last-Modified information associated with this cache entry.
 * \param entry The entry
 * \return The Last-Modified header (can be NULL)
 */
const char * gf_cache_get_last_modified_on_server ( const DownloadedCacheEntry entry );

/**
 * Set the Last-Modified header for this cache entry
 * \param entry The entry
 * \param newLastModified The new value to set, will be duplicated
 * \return GF_OK if everything went alright, GF_BAD_PARAM if entry is NULL
 */
GF_Err gf_cache_set_last_modified_on_disk ( const DownloadedCacheEntry entry, const char * newLastModified );

/**
 * Set the Last-Modified header for this cache entry
 * \param entry The entry
 * \param newLastModified The new value to set, will be duplicated
 * \return GF_OK if everything went alright, GF_BAD_PARAM if entry is NULL
 */
GF_Err gf_cache_set_last_modified_on_server ( const DownloadedCacheEntry entry, const char * newLastModified );

/**
 * Get the file name of cache associated with this cache entry.
 * \param entry The entry
 * \return The Cache file (never NULL if entry is valid)
 */
const char * gf_cache_get_cache_filename( const DownloadedCacheEntry entry );

/**
 * Get the real file size of the cache entry
 * \param entry The entry
 * \return the file size
 */
u32 gf_cache_get_cache_filesize( const DownloadedCacheEntry entry );

/**
 * Flushes The disk cache for this entry (by persisting the property file
 * \param entry The entry
 */
GF_Err gf_cache_flush_disk_cache( const DownloadedCacheEntry entry );

GF_Err gf_cache_set_content_length( const DownloadedCacheEntry entry, u32 length );

u32 gf_cache_get_content_length( const DownloadedCacheEntry entry);

/**
 * \brief append cache directives to an HTTP GET request
 * \param entry The entry of cache to use
 * \param httpRequest The HTTP GET request to populate. The request must have been allocated enough to handle the cache arguments
 * \return GF_OK if everything went fine, GF_BAD_PARAM if parameters are wrong
 */
GF_Err gf_cache_append_http_headers(const DownloadedCacheEntry entry, char * httpRequest);

/*
 * Cache Management functions
 */

 /*!
 * Computes the size of the cache elements in directory
 * \param directory containing cache files
 * \return size in bytes
 */
u64 gf_cache_get_size(const char * directory);

/*!
 * Delete all cached files in given directory starting with startpattern
 * \param directory to clean up
 * \return GF_OK if everything went fine
 */
GF_Err gf_cache_delete_all_cached_files(const char * directory);


/*
 * Cache Reader functions
 */

GF_CacheReader gf_cache_reader_new(const DownloadedCacheEntry entry);

GF_Err gf_cache_reader_del( GF_CacheReader handle );

s64 gf_cache_reader_seek_at( GF_CacheReader reader, u64 seekPosition);

s64 gf_cache_reader_get_position( const GF_CacheReader reader);

s64 gf_cache_reader_get_currentSize( GF_CacheReader reader );

s64 gf_cache_reader_get_full_size( GF_CacheReader reader );

s32 gf_cache_reader_read( GF_CacheReader reader, char * buff, s32 length);

Bool gf_cache_check_if_cache_file_is_corrupted(const DownloadedCacheEntry entry);

void gf_cache_entry_set_delete_files_when_deleted(const DownloadedCacheEntry entry);

Bool gf_cache_entry_is_delete_files_when_deleted(const DownloadedCacheEntry entry);

u32 gf_cache_get_sessions_count_for_cache_entry(const DownloadedCacheEntry entry);

u64 gf_cache_get_start_range( const DownloadedCacheEntry entry );
u64 gf_cache_get_end_range( const DownloadedCacheEntry entry );


Bool gf_cache_are_headers_processed(const DownloadedCacheEntry entry);
GF_Err gf_cache_set_headers_processed(const DownloadedCacheEntry entry);

/*! @} */

#ifdef __cplusplus
}
#endif

#endif /* _GF_CACHE_H_ */
